Animal feed composition containing antibiotic am374 as a growth promoter

ABSTRACT

ANTIBIOTIC AM374 PRODUCED BY FERMENTATION OF STREPTOMYCES EBUROSPOREUS N.S. IS USED AS A GROWTH PROMOTER FOR ANIMALS IN A CONVENTIONAL ANIMAL FEED.

April 9, 1974 FREQUENCY (CM M. P. KUNSTMANN ANIMAL FEED COMPOSITION CONTAINING ANTIBIOTIC AM574 AS A GROWTH PROMOTER Original Filed April 6; 1970 I600 1400 1200 M00 I000- 0 O (D o o S- o n 0 o o o co co Q 7 N (.LNQOHHd) BONVLLIWSNVUJ.

WAVELENGTH (MICRONS) INVENTORS MARTIN PAUL KUNSTMANN JOHN NORMAN PORTER ATTORNEY United States Patent 3,803,306 ANIMAL FEED COMPOSITION CONTAINING ANTIBIOTIC AM374 AS A GROWTH PROMOTER Martin Paul Kunstmann, Pearl River, N.Y., and John Norman Porter, Ramsey, N.J., assignors to American 3,803,306 Patented Apr. 9, 1974 Journ. of Syst. Bacteriol. 16: 313-340 (1966)]. Media used in the study were selected from those recommended by Pridham et al. [A Selection of Media for Maintenance and Taxonomic Study of Streptomyces. Antibiotics Annual (1956-1957), pp. 947-953] for the cultivation of 5 streptomycetes. Details are recorded in Tables I-IV, and

an m1 om an Stamford Conn. Apgi icai ion pn h, 970, Ser. No. 26,101, now Patent a general dfiscnpuon of the culture 15 glven 3,700,768, which is a confinuafiomimpart f h low. Descriptive colors were taken from Jacobson et a1. doned application Ser. No. 815,652, Apr. 14, 1969. [Color Harmony Manual 3rd ed. (1948)]. v Divided and this application June 22, 1971, Ser. No. Amount of growth-Moderate on most media; good 155,538 on potato dextrose agar; light on Czapeks solution agar. A61! 21/00 Aerial mycelium and/or en masse spore color.-Aerial 424-118 3 Clams mycelium whitish on most media; becoming Ivory (2 db) to Lt. Ivory (2' ca) in areas of sporulation. ABSTRACT OF THE DISCLOSURE Soluble pigments.Yellowish on several media; none Antibiotic AM374 produced by fermentation of on Czapeks solution, asparagine-dextrose and inorganic myces eburosporeus us. is used as a growth promoter for salts'starch agars' animalsin a conventional animal feed. Reverse color.In yellowish shades on most media.

Miscellaneous physiological reactions CROSS.REFERENCE o RELATED APPLICATIONS Nitrates not reduced to nitrites in organic nitrate broth; f complete liquefaction of gelatin in 7 days; melanin not app lcatlon 1S a mslon 0 our copen mg app 1c produced on peptone-iron agar. Carbon source utilizatron Ser. No. 26,101, filed Apr. 6, 1970, now US. Pat. fion accordin to the Pridham et al U No. 3 700 768 issued Oct. 24 1972 which in turn is a g .1

652 114 (1948)] method as follows: fair to good utilization commuanon'm'part of our apphcatlon 8 25 of l-arabinose, d-fructose, i-inositol, lactose, d-mannitol, filed 1969 now abandoned d-melibiose, salicin, d-trehalose, d-xylose; poor to non- BACKGROUND OF THE INVENTION utilization of l-rhamnose, adonitol, d-melezitose, d-raf- Th finose and sucrose.

e invention relates to an improved animal feed com h 1 position containing a new antibiotic which is effective in wromorp o ogy accelerating the growth rate of animals such as chicks, Aerial mycelium sparse, giving rise to long tangled and turkey poults, ducklings, etc., as well as young cattle, flexuous chains of elliptical to elongate spores 0.5 to horses, swine, dogs, and sheep. An effective omount of the 0.611. x 1.0 to 1.3 Spore surface smooth, as determined by new antibiotic is preferably added to a nutritionally balelectron microscopy. anced animal feed and fed to the animals to increase the On the basis of the general characteristics observed, growth rate thereof. Alternatively, the new antibiotic the microorganism becomes a member of the genus may be added to drinking water for ingestion by the ani- Streptomyces. A comparison of the culture NRRL 3582 mals as an aid in controlling infectious diseases. was madew ith all available reference specimens of other SUMMARY OF THE INVENTION streptomycetes having similar basic taxonomic features. Two species had several characteristics in common with The new antibiotic, which We have designated AM374, NRRL 3582; however, when the literature descriptions of is formed during the cultivation under controlled Condithese related species were examined, certain basic diiferfions of a 116W streptomycete isolated from a Soil Sample ences were found. These are set forth in Table V. In collected in Utah. A viable culture of the new microdditi n t the differences, NRRL 3582 generally proorganism has been deposited with the Culture Collection duces a markedly more restricted growth on most media Laboratory Northern Utilization Research and Developand its sporulation tends to be more sparse. ment Division, United States Department of Agriculture, It will be noted in Table V that the sporophore mor- Peoria, Ill. and has been added to its permanent collection. phology of NRRL 3582 is of the Rectus-Flexibilis type It is freely available in this repository under its Accession of Pridham et al. [AppL Microbiol. 6: 52-79 (1958)], No. NRRL 3582. whereas that of the other two species is Spira. This is a The description and identification of this new microvery fundamental difference, and it alone is adequate to organim, maintained in the culture collection of Lederle distinguish between the organisms. When considered to- Laboratories, Pearl River, N.Y., was supplied by Dr. H. gether with the other differences indicated, NRRL 3582 D. Tresner of these laboratories. stands out sufficiently from the others to be regarded as a Observations were made of the cultural, physiological 55 separate species. I I and morphological features of the culture in accordance In keeping with the ivory color of the spores produced with the methods detailed by Shirling et al. [Methods for by the organism, the name Streptomyces eburosporeus n.s. Characterization of Streptomyces Species, Internat. is proposed as an appropriate descriptive epithet.

TABLE I Cultural characteristics of Streptomyces eburosporeus n.s. N RRL 3582 Incubation, 14 days Temperature, 28 0.

Amount of Medium growth Aerial mycelmm and/or spores Soluble pigment Reverse color Remarks Czapeks solution Light Aerial mycelium whitish, becoming None Lt. Melon Yellow (3 Growth restricted.

agar. Ivory (2 db) to Lt. Ivory (2 ca) in ca).

sporulation zones. Sporulation light. Asparagine dextrose Moderate--- Aerial mycelium whitish, sparse. No .do Bamboo (2 tb) Growth restricted; colony agar. sporulation. edge serrate. Hickey and do Aerial mycelium whitish, becoming Yellowrsh; light.-. Lt. Amber (3 ic) Surface growth paplllose.

Tresners agar. Ivory (2 db) to Lt. Ivory (2 ea) in sporulation zones. Sporulation light. Yeast extract agar --do Aen'tal mycelium whitish; trace of sporu- .....do Lt. Amber (3 ic) Surface rugose.

a ion.

I 7 TABLE ICntlnned Amount of Medium growth Aerial mycelium and/or spores Soluble pigment Reverse color Remarks Kusters oatfiake -do- Aerial mycelium whitish, becoming Yellowish-hrown; Lt. Melon Yellow (3 Moderate starch hydrolysis.

agar. Ivory (2 db) to Lt. Ivory (2 ca) in light.

sporulation zones. Sporulation light. ea). Tomato paste, oatdo.. do--- Orange-yellow; Lt. Amber (3 is) Surface papillose.

meal agar. moderate. Potato dextrose Good.---..- Aerial mycelium whitish, sparse, bedo do Starch hydrolysis light. Col agar. coming Ivory (2 db) in Lt. Ivory (2 ca) ony surface rugose to in sporulation zones. Sporulation light. n'mose. Bennett's agar Moderate- Aerial mycelium whitish, sparse. Trace Yellowish; light do Surface wrinkled and papilof sporulation. lose. Inorganic salts .do Aerial mycelium whitish, becoming None Lt. Melon Yellow (3 starch agar. Ivory (2 db) to Lt. Ivory (2 ca) in ca).

sporulation zones. Sporulation light.

- TABLE II Micromorphology of Streptomyces ebumsporeus n.s. NRRL 3582 Aerial mycelium and/0r Medium sporiferous structures Spore shape Spore size Spore surface Kusters oatflake agar-.-" Aerial mycelium sparse, giving rise to Elliptical to el0ngate Spores 0.5"0-6/l x 1.0-1.3 Smooth as determined long tangled and flexuous chains of by electron spores. microscopy.

TABLE III Miscellaneous physiological reaction of Streptomyces eburoaporeus n.s. NRRL 3582 Temperature, 28 C.

Incubation Amount of Physiological Medium period growth reaction Organic nitrate broth. 7 days Good No nitrate reduction.

Do 14 days do ,Do. Gelatin- 7 days dn Complete liquefaction. Peptone-iron agar 24 hours Moderate Melanin not produced.

TABLE IV The fermentation process Carbon source utilization pattern of Streptomyces Cultivation of the organism S. eburosporeus may be eburosporeus n.s. NRRL 3582 carried out in a wide variety of liquid culture media.

Media which are useful for the production of the novel antibiotic include an assimilable source of carbon such Carbon Source; U ili i as starch, sugar, molasses, glycerol, etc.; an assimilable Incubation: 10 days. Temperature: 28 C.

Ad iml 0 source of nitrogen such as protein, protein hydrolysate, 1- bin 3 4O polypeptides, amino acids, corn steep liquor, etc.; and d..Fructos 2 inorganic anions and cations, such as potassium, sodium, u it l 3 calcium, sulfate, phosphate, chloride, etc. Trace elements L t 3 such as boron, molybdenum, copper, etc.; are supplied as d-Mannitol 3 impurities of other constituents of the media. Aeration d-Melezitose 0 in tanks and bottles is provided by forcing sterile air d-Melibiose 3 through or onto the surface of the fermenting medium. d-Raflinose 0 Further agitation in tanks is provided by a mechanical l-rhamnose 1 impeller. An antifoaming agent, such as 1% octadecanol, Salicin 3 in lard oil may be added as needed.

i ig iz g 'l g Inoculum preparation d-Xylose 3 Shaker flask inoculum of S. eburosporeus is prepared Dextrose 3 by inoculating 100 milliliters of sterile liquid medium in Negative control 0 500 milliliter flasks with scrapings or washngs of spores 1 3, Good utilization 2, fair utilization 1, poor utilization g 5 g of the culture The following medium 0, no utilization. 15 or 1131' Y use TABLE V Comparison of Streptomyces NRRL 3582, with S. albidoflaoua and S. oliorlfer Streptomyces NRRL 3582 S. albidoflavu: S. odorz'fzr Aerial mycelium and/or spore-bearing Sporophores long, fiexuous and Sporophores short, splrel-forming--. Sporophores long, straight,

branches. tangled. branching; forming spiral.

Spore shape Elliptical to el g Sp Sperlcal.

Gelatin liquefaction. Complete liquefaction Rapid liquefaction Slow liquefaction.

Soluble pigments Mostly yellowish Mostly yellowish Mostly brownish.

Growth on asparaglne-dextrose agar-.- Growth yellowish; aerial mycelium Growth brown; aerial mycellum be- Growth cream colored to brownish.

whitish, sparse. coming whitish-yellow. Aerial m llceliium abundant,

cream-co ore It is to be understood that for the production of the new antibiotic the present invention is not limited to this 2 3 2322 5 particular organism or to organisms fully answering the abov d ch t h Bactopeptone g 5 e growth an microscopic arac ens 105 w 1c are Water to m] 1,000

given for illustrative purposes. In fact, it is desired and i d to include the use f mutants produced f o The flasks are incubated at a temperature from 2529 the described organisms by various means, such as X-radia- 's Preferably -s and agitated vigorously on a rotary tlon, ultraviolet radiation, nitrogen mustard, phage exshaker for'30 to 48 hours. These 1-00 milliliter inocula posure and the like. are used to inoculate 1 liter and 12 liter batches of the same medium in 2. liter and 20 liter glass fermentors. The inoculum mash is aerated with sterile air while growth is continued for 30 to 48 hours. These batches of inocula are used to inoculate tank fermentors.

Tank fermentation For the production of the antibiotic in tank fermentors the following fermentation medium is preferably used.

G. Soy bean flour Cerelose 10 Sodium chloride 5 Calcium carbonate 1 Distillers solubles from corn 5 Water to 1,000 milliliters.

Purification procedure After the fermentation is completed, the fermented mash containing the antibiotic of this invention is filtered, preferably at pH 6, to remove the mycelium. Diatomaceous earth or any other conventional filtration aid may be used to assist in the filtration. Normally the mycelial cake is washed with water and the wash is pooled with the filtrate. The antibiotic activity is adsorbed onto Darco G-60, or other suitable charcoal adsorbant, using 0.5% (weight/volume) of the adsorbant. The antibiotic activity retained on the charcoal may be eluted by stirring the charcoal for about one-half hour with 40% aqueous acetone adjusted to pH 2 with concentrated sulfuric acid, using a volume of eluate equal to about one-quarter of the original beer volume. The eluate is concentrated under reduced pressure to an aqueous phase equal to about one-twentieth of its original volume. The pH of this phase is adjusted to about 5.5 with barium hydroxide and the barium sulfate precipitate which forms is removed by filtration. The adjusted solution (filtrate) is further concentrated to about 400-800 ml. This concentrate is then slurried with acidified alumina (using about one-fifth of the amount of alumina in grams as compared to the volume of concentrate) and this slurry is poured onto a suitable column of acidified alumina, using approximately ten times the amount of alumina used in the charge) wet-packed in methanol. The antibiotic activity is eluted from the column with aqueous methanol (usually 25-50%) and appropriate active fractions are collected. The active fractions are combined and concentrated to a small volume (one liter or less) under reduced pressure. The pH of this concentrate is adjusted to about 6.0 to 6.5 with barium hydroxide. Again, the barium sulfate precipitate which forms is removed by filtration and the clear filtrate lyophilized to yield the (crude) antibiotic AM374. This lyophilized material is now further purified by column chromatography on a suitable ion exchange resin, as for example, CM Sephadex C-25 (H+ form). The column may be eluted using dilute sulfuric acid solutions. The eluate containing the antibiotic activity, located by absorption at 280 mu, is adjusted to about pH 6.3 with barium hydroxide. The barium sulfate precipitate which forms is removed by filtration and the filtrate is concentrated to a volume of about 30-80 milliliters. The pH of this solution is adjusted to about 8.0 with IR45 (011-) resin. The resin is removed by filtration and the filtrate is added to a larger quantity of acetone with stirring and the precipitate which forms is recovered by filtration. The precipitate is washed with acetone and dried at moderate temperature under reduced pressure to yield antibiotic AM374 in the base form.

Physical Characteristics A microanalytical sample may be prepared by precipitating AM374 base from methanolic and/or ethanolic acetone and drying the precipitate under high vacuum 10- mm.) at 100 C. for two days. Antibiotic AM374 base prepared in this manner contains the elements carbon, hydrogen, oxygen, nitrogen and chlorine in substantially the following percentages by weight:

Percent by Wt. Carbon 54.54 Hydrogen 6.10 Oxygen 29.01 Nitrogen 7.60 Chlorine 2.47

The material does not have a definitive melting point, decomposing slowly above 250 C. Optical rotation is [a] 25".=. 102 ($2.9) (C=1.045 in water). Ultraviolet maxima occur at:

282 III l. (E}Z" =42) in acidic solutions, 282 m (E}Z" =42.5) in neutral solutions, 305 mu. (El'' ,=51.5) in basic solutions, sh.260 m (E}'Z' =92) in basic solutions.

An infrared absorption spectrum of AM374 base in a KBr pellet, prepared in a standard manner, exhibits characteristic absorption at the following wavelengths expressed in microns: 3.0, 3.43, 6.0, 6.20, 6.30, 6.67, 6.88, 7.05, 7.22, 7.35 sh., 7.52, 7.67, 8.2, 8.65 sh., 8.85, 9.45, 9.75, 9.90, 10.45 sh., 11.07, 11.5, 12.0, 12.35,.13.35, 14.4. The infrared curve is shown in the accompanying drawing.

AM374 antibiotic shows the following R, values in the solvent systems indicated below using Bacillus sub-tilts pH 6.0 or Corynebacterium xerosis as detection organisms:

R value: Solvent system 0.90 5% aqueous NH CI 0.20 pyridine 2 parts s-collidine 2 parts sec-butanol 1 part water 1 part TABLE VI In vitro antimicrobial activity of Antibiotic AM374 and its hydrolysis product Minimal inhibitory concentrations (micrograms per ml.)

Antibiotic Hydrolysis AM374 product Staphylococcus aureus ATCC 65381 3. 1 0. 2 Staphylococcus aureus No. 69 3. 1 3. 1 Staphylococcus aareus, Rose ATCC 14154.-. 6. 2 o. 2 Staphylococcus aureus, Smith ATCC 13709-. 6. 2 6.2 Streptococcus pyogenes C203 0.62 1 25 Streptococcus faecalia ATOC 8043 3.1 2 Streptococcus sp., nonhemolytic No. 6. 2 2 Streptococcus sp., B-hemolytic No. 80.. 6. 2 2

Mueobactertum smeqmatis ATCC 607 Proteus valaaris A'ICC 9484-.. Escherichia coli U311--. Escherichia coli DY Klebstella pneumontae, strain AD Entcrobacter oeroaenea No. Pseudomohaa aeraainosa ATOC 10145 1 Using agar dilution method.

AM374 is active in vivo also against a variety of grampositive microorganisms such as staphylococci, pneumococci, and streptococci. The new antibiotic is thereby potentially useful as a therapeutic agent in treating bacterial infections in mammals caused by such microorganisms. The new antibiotic can be expected to be usefully employed for treating or controlling such infections by topical application or parenteral administration.

The usefulness of the new antibiotic is demonstrated by its ability to control systemic lethal infections in mice. The new antibiotic shows high in vivo antibacterial activity in mice against Staphylococcus aureus, strain Smith; Staphylococcus aureus, strain Rose; Streptococcus pyogenes, C203; and Diplococcus pneumoniae, SVl when administered by a single subcutaneous dose to groups of Carworth Farms CF-l female mice, weight about 20 grams, infected intraperitoneally with a lethal dose of these bacteria in 10*, 10, 10- 10 trypticase soy broth TSP dilutions, respectively, of a five hour TSP blood culture.

Table VH, below, illustrates the in vivo antibacterial activity of AM374 while Table VIII, following, illustrates the in vivo antibacterial activity of the hydrolysis product.

TABLE VTL-IN VIVO ANTIBACTERIAL ACTIVITY OF ANTIBIOTIC AM374 Aliveltotalmlce, 14 days after infection Staphylococcus aureus Strepto- D /k st 81 St coecua Diplococcius osage mg. g. r n ram pvoaenca pmumon as body wt. Smith Rose 0203 I SVl Norn.i the infected non-treated control mice ad-100% died within days after infection.

TABLE VIII.--IN VIVO ANTIBACTERIAL ACTIVITY OF AM374-HYDROLYSIS PRODUCT Alive/total mice, 14 days after infection Staphylococcus aureus strain Smith As indicated earlier, the novel antibiotic is highly effective in promoting the growth rate of animals. In carrying out the present invention, an effective amount of the novel antibiotic is added to drinking water or preferably a nutritionally balanced animal feed and is fed to the animals to increase the growth rate thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will be described in greater detail in conjunction with the following specific examples.

EXAMPLE 1 Inoculum preparation A typical medium used to grow the primary inoculum was prepared according to the following formula;

Molasses g 20 Glucose g Bactopeptone g 5 Water to ml 1,000

The washed or scraped spores from an agar slant of S. eburosporeus were used to inoculate two flasks containing 100 milliliters each of the above medium. in 500 milliliter flasks. The flasks were placed on a rotary shaker and agitated vigorously for 48 hours, at 28 C. The resulting flask inoculum was transferred to a 5 gallon glass fermentor containing 12 liters of sterile medium. The glass fermentor was aerated with sterile air while growth was carried out for about 48 hours, after which the contents were used to seed a 300 liter tan-k fermentor.

EXAMPLE 2 Fermentation A fermentation medium was prepared according to the following formula:

The fermentation medium was sterilized at 120 C. with steam at 15 pounds pressure for 45-60 minutes. The pH of the medium after sterilization was 6.6. Three hundred liters of sterile medium in a 400 liter tank fermentor was inoculated with 12 liters of inoculum such as described in Example 1, and the fermentation was carried out at 28 C. using Hodag LG-8 oil as a defoaming agent. Aeration was supplied at the rate of 0.5 liter of sterile air per liter of mash per minute. The mash was agitated by an impeller driven at 300* revolutions per minute. At the end of approximately hours of fermentation time the mash was harvested.

EXAMPLE 3 Isolation and purification 300 liters of fermented mash were filtered with about 2% (W./y.) of diatomaceous earth filter aid and the filter pad was washed with about 30 liters of water. The fermented mash was previously adjusted to pH 6.0 with .sodium hydroxide. The antibiotic activity in the pooled filtrate and water wash was adsorbed onto 900 grams of Darco G450 and colored impurities were removed from the charcoal suspension by stirring with about 30 liters of 40% aqueous acetone. The activity was eluted from the charcoal by stirring with liters of 40% aqueous acetone adjusted to pH 2.0 with concentrated sulfuric acid. The suspension was filtered, the eluate was concentrated under reduced pressure to about 4 liters of aqueous phase and the pH was adjusted to 5.2 with barium hydroxide. The barium sulfate precipitate was removed by filtration and the filtrate further concentrated to about 700 ml. This concentrate was slurried with 100 g. of acidtreated alumina and poured onto a column consisting of 1 kg. acid-treated alumina in methanol. The acid-treated alumina was prepared by acidifying an aqueous slurry of Merck alumina with concentrated sulfuric acid until a constant pH of 3.0 was obtained, filtering, washing with water and methanol, and air drying. The column was then eluted with 5 liters of methanol followed by 60 liters of 50% aqueous methanol followed by 10 liters of 25% aqueous methanol. Appropriate fractions containing antibiotic AM374, determined by bioassay against C. xeraszs, were combined and concentrated under reduced pressure to about 500 ml. and the pH was adjusted to 6.2 with barium hydroxide. The barium sulfate precipitate was removed by filtration and the filtrate lyophilized to give 5.1 grams of crude AM374 (about 30 to 50% pure).

The 5.1 grams of crude AM374 thus obtained was dissolved in 30 m1. of water and applied to a column of CM Sephadex C-25 (H+ form). The Sephadex (250 g.) was prepared for use by being slurried in about 3 liters of water and the pH adjusted to 2.0 with concentrated H The excess water was decanted and the resin washed several times with water. The slurry was poured into a column (7.6 cm. LB.) and washed with an additional 5 liters of water removing the excess acid.

The column was eluted with a gradient between 4 liters of water and 4 liters of water adjusted to pH 1.4 with concentrated sulfuricacid, followed by an additional 4 liters of water adjusted to pH 1.4. Fractions (about 100 ml. each) were collected and bioactivity (C. xerosis) and ultraviolet absorbance (280 mg) were measured on 1 to 100 dilutions of these fractions.

Fractions 58 through 80 were shown to contain the majority of the desired antibiotic and were combined into one pool. The pH of this pool was adjusted to 6.3 with barium hydroxide and the precipitated barium sulfate was removed by filtration with the aid of diatomaceous earth. The filtrate was concentrated to about 200 ml. and lyophilized yielding about 1.5 grams of crude antibiotic. The crude antibiotic was dissolved in 50 ml. of water and the pH of the solution was adjusted to about 8.2 with IR45 (OH form). The suspension was filtered and the filtrate was lyophilized. The lyophilizate was dissolved in 40 ml. of water and the antibiotic was precipitated upon the addition of 400 ml. of acetone. The crystalline precipitate was collected by filtration and dissolved in a small portion of methanol. Addition of acetone precipitated the purified antibiotic AM374 which was collected by filtration, yield 1.18 grams.

A microanalytical sample was prepared by precipitation of AM374, obtained as described above, from ethanolic acetone and drying the precipitate under high vacuum (10- mm.) at 100 C. for two days. The chemical analysis of this product and the other physical and biological properties of the new antibiotic have already been described.

EXAMPLE 4 Conversion of AM374 base into AM374 sulfate One hundred and fifty milligrams of AM374 base was dissolved in 60 ml. of warm methanol to which was added one drop of a 1:1 methanol-concentrated sulfuric acid solution. The resulting precipitate was filtered and washed with some methanol and acetone to give 98 mg. of AM374 sulfate.

Alternatively, AM374 sulfate was prepared by adjusting an aqueous solution of AM374 base to about pH 6.3 with sulfuric acid, followed by precipitation with acetone.

A microanalytical sample was prepared by precipitation from aqueous acetone and drying the precipitate under high vacuum (10- mm.) at 100 C. for two days. AM374 sulfate prepared in this manner contains the elements carbon, hydrogen, oxygen, nitrogen, sulfur and chlorine in substantially the following percentages by weight:

Carbon 51.68 Hydrogen 5.85 Oxygen 30.25 Nitrogen 7.02 Sulfur 1.36 Chlorine 2.27

Optical rotation is [oz] l04 (1:2.8") (c.=l.075 in water). Ultraviolet maxima occur at:

EXAMPLE 5 Conversion of AM374 base into AM374 chloride Two hundred milligrams of AM374 base was dissolved in ml of 0.1 N hydrochloric acid and concentrated to Carbon 52.20 Hydrogen 6.22 Oxygen 28.03 Nitrogen 7.26 Chlorine 6.34

Optical rotation is [a] 106 (12.8") (c.=1.057 in water). Ultraviolet maxima occur at:

282 m (Ei?a=42) in acidic solutions, 282 my. (E} =39.5) in neutral solutions, 305 m (EiZ' =52) in basic solutions, sh.260 m (E}Z;;, =92) in basic solutions.

An infrared absorption spectrum of AM374 chloride in a KBr pellet, prepared in a standard manner, exhibits characteristic absorption at the following wavelengths expressed in microns: 3.0, 3.27, 3.40, 5.75 sh., 5.90 sh., 5.98, 6.15, 6.28, 6.65, 6.82 sh., 7.03, 7.15, 7.50, 7.65, 8.25, 8.60, 8.83, 9.42, 9.70, 9.88, 10.45 sh., 11.05, 11.9, 12.3, 13.3, 14.7.

EXAMPLE 6 Acid hydrolysis product of AM374 base One gram of AM374 antibiotic base was dissolved in 7.5 ml. of boiling water. To this was added 1.25 ml. of 5 N hydrochloric acid and the resulting solution boiled an additional 2 to 3 minutes. An additional 2 ml. of 5 N hydrochloric acid was added and the solution was cooled. This was filtere and the precipitate washed with a total of 3 ml. of 5 N hydrochloric acid. It was redissolved in water and concentrated to a residue. This was repeated twice more after which the residue was precipitated from aqueous acetone to give 516 mg. of acid hydrolysis product. I A microanalytical sample was prepared by precipitatron from aqueous acetone and drying the precipitate under high vacuum (10* mm.) at C. for two days. The AM374 hydrolysis product prepared in this manner contains the elements carbon, hydrogen, oxygen, nitrogen and chlorine in substantially the following percentages by weight:

Carbon 52.54 Hydrogen 5.8 1 Oxygen 25.52 Nitrogen 8.32 Chlorine 7.1 1

Optical rotation is [a] =--69 (1:3.6) (c.=0.839 in water). Ultraviolet maxima occur at:

280 m (E}Z,, =46) in acidic solutions, 280 m (E}Z' ,=51.5) in neutral solutions, 300 mu. (E}Z =8fi) in basic solutions, sh.260 m (E}'Z; 143) in basic solutions.

".1 1 EXAMPLE 7 The basal diet employed in the following poultry tests had the following composition.

Poultry basal diet Trace minerals are manganese (6.0%), iodine (.12%), iron (2.0%), copper (2%), zinc (2.0%), cobalt (.02%), and calcium (25.5%).

{Vitamin pre-mlx, per kg. of feed, contains 125 mg. butylated hydroxy toluene, 500 mg. DL-methionine, 3800 LU. Vitamin A, 1100 LU. Vitamin Da, 2.2 I.U.'Vitamin E, 11 mcg. Vitamin Bu, 4.4 mg. riboflavin, 27.5 mg. niacin, 8.8 mg. Panto thenic acid, 500 mg. choline chloride,-1.43 mg. follc acid, and 1.1 mg. menadione sodium blsulflte to 5 g. of ground yellow corn.

' Day-old chicks (6 males and 6 females per group) purchased from a commercial supplier are housed in heated brooders and held in a chick room maintained at about 24 C. All chick groups are weighed at the start of the tests and on termination at 20 days. Feed and water are supplied ad libitum. The basal diet described aboveis used for all tests. Treatments used were (a) untreated controls, (b) 10 p.p.m. AM374, (c) 2 p.p.m. AM374. Data obtamed are reported below where it can be seen We claim: a 1. An animal feed composition effective in accelerating the growth rate of animals which comprises a nutritionally balanced animal feed containing an eifective amount of antibiotic AM374, a compound which (a) is effective in inhibiting the growth of gram-positive bacteria, and in its essentially pure crystalline form; (b) is readily soluble in water and dimethyl sulfoxide 10 and moderately soluble in methanol and ethanol and relatively insoluble in other common organic solvents;

(c) has the following elemental analysis: C, 54.54; H,

6.10; O, 29.01; N, 7.60; CI, 2.47;

(d) has ultraviolet maxima at:

282 mu. (E'i" ,=42) in acidic solutions, 282 m (E}? =42.5) in neutral solutions, 305 m (E}Z' ,==51.5) in basic solutions,

sh260 my. (Ei? =92) in basic solutions;

(e) has'an optical rotation: [a] =--102 ($29") (c.=1.045 in water); and (f) has a characteristic infrared absorption spectrum as shown in the drawing. 2. A feed for animals containing at least 2 ppm. of antibiotic AM374 as defined in claim 1.

3. A process for increasing growth rate and for improving feed efiiciency in animals which comprises feeding animals a nutritionally balanced animal feed containing that at both treatment levels AM374 showed a marked an etlective amount of antibiotic AM374 as defined in improvement in the growth of treated birds.

claim 1.

EFFICIENCY BY CHICKg RECEIVING RATIONS CONTAINING AM374H ROWTH AND FEED References Cited Chem. Abst., Seventh Collective Index, vol. 56-65 SAM ROSEN, Primary Examiner US. Cl. X.R. 

